The Russian Dictionary Tree by Slava Paperno and Richard L. Leed is a reference and learning tool
for all students of Russian, from those with only basic knowledge of the language to the learner
who is proficient enough to write in Russian. It is called a "tree" because
its entries have a tree-like, branching structure, and because it keeps growing.

The Tree is not an abridged version of a printed dictionary:
it was created as an on-screen reference
source and designed to fully use the advantages of the electronic medium. If printed in a book format, this edition
would have occupied over a thousand pages. In most entries, the user will find lexicographical information
compiled from many sources. Many entries contain data not usually included in dictionaries,
such as combinatorial and sociolinguistic information.

Even though one can look up many English words, The Tree is not an English-Russian dictionary.
The English-to-Russian component merely provides the user with an English index to the Russian entries.
The difference is an important one. All Russian entries are semantically complete. That is, if a Russian word
is listed, the viewer will see all of its meanings defined, glossed, and often commented on.
Only the most obscure or technical meanings have been left out. This is not so with the English word list.
Since English words are merely glosses for Russian headwords, a meaning will be absent when no Russian entry requires its presence.